[Bug]: APIRequestContext cookie path matching is too permissive (RFC 6265 §5.1.4) #43160

Version

main (1.65.0-next, 6936b23)

Steps to reproduce

1. A response sets Set-Cookie: a=1; Path=/foo/. A subsequent request.get('http://host/foo') sends a=1.
2. request.cookies('http://host/foobar') returns a cookie with Path=/foo.

Expected behavior

Per RFC 6265 §5.1.4 (and browser behavior), request path /foo does not path-match cookie path /foo/, and /foobar does not path-match /foo (the next char after the cookie path must be / unless the cookie path ends with /).

Actual behavior

• pathMatches in server/cookieStore.ts appends / to the request path before comparing, so /foo matches /foo/ and the cookie is sent.
• filterCookies in server/network.ts (used by cookies(urls)) uses a bare pathname.startsWith(c.path), so /foobar matches /foo.

Additional context

Pre-existing, but more visible now that APIRequestContext.cookies() is public (#43052). Low severity.

Environment

Playwright main @ 6936b230a (1.65.0-next). Found by code review of recent commits; not OS/browser specific.